1. Field of the Invention
The present invention relates to a wireless network access system, and more particularly, a WLL-WLAN integrated network system which allows Internet access and constructs a network wirelessly by combining a wireless LAN and a wireless local loop (WLL) employing a wideband code division multiple access (W-CDMA) scheme.
2. Background of the Related Art
Currently, a W-CDMA system called a third-generation partner projection (3GPP) or a third-generation (3G) mobile wireless technology requires access to a core network such as PSTN, ISDN, IMT-2000, PSDN, the Internet, WAN/LAN, etc., through its own network for a wireless (radio) telecommunication.
A wireless telecommunication network system is largely classified into a mobile communication network and a wireless local loop (WLL) according to an application field. The mobile communication network can support data communication at transmission rates of up to about 384 Kbps during movement of a mobile and portable wireless device and up to about 2 Mbps during a stop thereof, and the wireless local loop (WLL) can support a data communication at a transmission rate of up to about 2 Mbps.
Also, the wireless local area network (WLAN) specified by a standard, IEEE 802.11b can support data communication at up to 11 Mbps, but requires a connection to an Ethernet switch using a cable line for the data communication.
FIG. 1 is a broad block diagram illustrating the construction of an Internet access system independently employing a wireless local loop (WLL) and a wireless local area network (WLAN) according to the related art.
As shown in FIG. 1, a general Internet access system 30 of a wireless local loop (WLL) includes a WLL base station 20 connected to the core network (hereinafter, referred to as “Internet”) 10 and a plurality of WLL terminals (32 and 34) connected to the WLL base station 20 wirelessly. The WLL terminals (32 and 34) include a mobile WLL terminal 34 connected to a lap top computer and a fixed WLL terminal 32 connected to a desk top computer.
Basically, the WLL is not much different from a cellular communication system or a personal communication system in the aspect that a base station and a terminal transmit and receive a data to each other wirelessly. It is a telecommunication network constructed using a radio system instead of a wired line which connects the core network and a terminal of a network subscriber. This technique was first developed by the Bell Atlantic Network Services, Inc. (Arlington, Va.) of the United States in the early 1970's as a method for cutting down on a facility expense in constructing a telecommunication network in a sparsely populated area such as a farming area or a remote mountain village. Currently, however, with the advanced radio technology and as the WLL draws more attention, its utilization coverage and installation area are being widened. Thanks to its advantages of a low unit cost per line and easy installation compared with a wired line, it is in increasing demand.
FIG. 2 is a block diagram of a radio transceiver of a WLL terminal according to the related art. As shown in FIG. 2, the radio transceivers of the WLL terminals 32 and 34 employ a diversity antenna, respectively and a radio-frequency, electromagnetic signal received by each diversity antenna is converted into an electrical signal which is supplied to a band pass filter (BPF)110 and a duplexer 240 which apply only a necessary frequency band of the electrical signal to low noise amplifiers (LNAs) 120 and 125, respectively, to amplify the necessary frequency band. The amplified signals generated from the low noise amplifiers (LNAs) 120 and 125 are applied to down mixers 130 and 135 which down-convert in frequency the amplified signals to form intermediate frequency signals, respectively. Then, the down-converted signals generated from the down mixers 130 and 135 are applied to automatic gain controller (AGC) and demodulators 140 and 145 which amplify the down-converted signals to a proper level and demodulate the amplified signals. The signals generated from the automatic gain controller (AGC) and demodulators 140 and 145 are applied to low pass filters (LPFs) 150 and 155 which reject noise components of the signals applied thereto from the automatic gain controller (AGC) and demodulators 140 and 145 for application to A/D converters 160 and 165. The A/D converters 160 and 165 convert the noise-rejected signals into digital signals for application to a digital baseband processor 170 which, in turn, applies the converted digital signal to a personal computer (PC) 180 so that a user can receive data on the Internet 10.
In the meantime, the data transmitted from the personal computer (PC) 180 is transmitted to the digital baseband processor 170, and then a D/A converter 190 which converts the data transmitted thereto into an analog signal for application to an automatic gain controller (AGC) and modulator 200. The automatic gain controller (AGC) and modulator 200 controls the-gain of the converted analog signal to a proper level and modulates the converted analog signal for application to a band pass filter (BPF) 210 which, in turn, rejects noise components of the signal applied thereto from the automatic gain controller (AGC) and demodulator 200 for application to an up mixer 220. The up mixer 220 up-converts in frequency the signal applied thereto from the band pass filter (BPF) 210 for application to a high power amplifier (HPA) 230. The high power amplifier (HPA) 230 sufficiently amplifies the output of the up-converted signal applied thereto from the up mixer 220 so that it can be sent out by radio for application to the duplexer 240 which, in turn, transmits the amplified signal applied thereto from the high power amplifier (HPA) 230 again to the WLL base station 20. However, in case of such a WLL Internet access system 30, there has been a problem in that a plurality of WLL terminals 32 have difficulties in accessing the Internet simultaneously.
As shown in FIG. 1, a general Internet access system 40 of a wireless local area network (WLAN) includes a HUB 44 connected through wire to the Internet 10, a wireless access point 46 connected through wire to the HUB 44 for enabling a wireless data transmission between the HUB 44 and a plurality of WLAN terminals 42, and the plurality of WLAN terminals 42 included in a mobile or fixed computer for connecting to the wireless access point 46.
A conventional WLAN Internet access system 40 constructed as described above can enable a data communication with the Internet 10 at a transmission rate of up to 11 Mbps by means of the HUB 44 connected to the Internet 10 through a cable line and the wireless access point 46 for driving the plurality of WLAN terminals 42, for example, 10 WLAN terminals.
FIG. 3 is a block diagram of a WLAN access point according to the related art. As shown in FIG. 3, data transmission from the WLAN Internet access system 40 is performed by a half duplex scheme in which a medium access controller (MAC) 175 controls a dual switch 280 to determine whether to transmit or receive a signal.
In the case where the dual switch 280 selects a receiving antenna, a radio-frequency, electromagnetic signal received by the selected receiving antenna is converted into an electrical signal supplied to a low noise amplifier (LNA) 128 through the dual switch 280. The low noise amplifier (LNA) 128 amplifies the electrical signal applied thereto from the selected antenna for application to a band pass filter (BPF) 213 which, in turn, passes only a necessary frequency band of the amplified signal. The filtered signal generated from the band pass filter (BPF) 213 is applied to a down mixer 138 which converts downward in frequency the filtered signal into an intermediate frequency signal. Then, the converted intermediate frequency signal generated from the down mixer 138 is applied to an automatic gain controller (AGC) and demodulator 148 which demodulates the intermediate frequency signal. The demodulated signal generated from the automatic gain controller (AGC) and demodulator 148 is applied to an A/D converter 168 which converts the demodulated signal into a digital signal. The converted digital signal is applied to a computer (PC) 188 through the medium access controller (MAC) 175 so that a user can receive data on the Internet 10.
In the meantime, the signal transmitted from the computer (PC) 188 is processed by the medium access controller (MAC) 175 which applies the processed signal to a D/A converter 198. The D/A converter 198 converts the signal applied thereto from the medium access controller (MAC) 175 into an analog signal for application to an automatic gain controller (AGC) and modulator 208 which modulates the converted analog signal. The modulated analog signal is applied to a up mixer 228 which up-converts in frequency the modulated signal applied thereto from the automatic gain controller (AGC) and modulator 208 for application to a band pass filter (BPF) 218 which, in turn, rejects noise components of the up-converted signal for application to a high power amplifier (HPA) 238. The high power amplifier (HPA) 230 amplifies the signal applied thereto from the band pass filter (BPF) 218 to transmit the amplified . signal to the wireless access point 46 by way of the dual switch 280. At this time, the signal received by the wireless access point 46 is transmitted to the HUB 44, and then the Internet 10 through wire.
However, in case of such a WLAN Internet access system 40, there has been a problem in that the HUB 44 must connect to the Internet 10 through a cable line, and the WLL Internet access system 30 and the WLAN Internet access system 40 have been operated as independent network systems.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background. cl SUMMARY OF THE INVENTION
An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
Therefore, the present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a plurality of users with a integrated wireless local loop (WLL) and wireless local area network (WLAN) Internet access system which combines a wireless local loop (WLL) and a wireless local area network (WLAN) which have been operated independently of each other at a small-scale office or a home office for small office home office (SOHO).
According to the present invention, there is provided an integrated wireless local loop (WLL) and wireless local area network (WLAN) transceiver apparatus which connects a wireless local loop (WLL) base station and a plurality of wireless local area network (WLAN) terminals, including a WLL transceiver in communication with a WLL base station, a WLAN transceiver in communication with wireless terminals, and a means for translating signals between the WLL signal protocol and the WLAN signal protocol.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.